SiO2@SnO2/graphene composite with a coating and hierarchical structure as high performance anode material for lithium ion battery

In order to ease the agglomeration and huge volume change of SnO2 particles, SnO2 nanoparticles were usually anchored on reduced graphene oxide (rGO) and used as anode materials for lithium ion batteries. Unfortunately, graphene sheets tended to overlap with adjacent ones and SnO2 nanoparticles still suffered from agglomeration and huge volume changes to some extent. In this paper, a composite SiO2@SnO2/rGO with coating and hierarchical structure was synthesized by a facile hydrothermal method. SnO2 nanoparticles mono-dispersed on the surface of rGO sheets and SiO2 spheres, while the SiO2@SnO2 spheres were imbedded in the layers of rGO, which was in favor of alleviating the overlapping of graphene sheets and could make large spacious room to accommodate the huge volume changes of SnO2 nanoparticles. SiO2@SnO2/rGO composite also displayed good electrochemical performance. In the first charge/discharge cycle, the SiO2@SnO2/rGO electrode exhibited a large discharge capacity of 1548 mA h g−1 at a current density of 100 mA g−1 and it still retained a discharge capacity of about 600 mA h g−1 after 100 cycles.